Tapping-machine.



J. M. LARSUN.

TAPPNG MACHINE.

yAPPLHMAIQN FIL-ED JULY 20. 1908.

934,40? Patente@ sept, 14,1909.

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TO'HN M. LARsoN, ori GHICAGO, ILLINOIS, AssIGNoR or ONE-HALIE1I To WALTER W.

CURTIS, 0F CHICAGO, ILLINos.-

TAPPING-MACHI'N'E.

Specification f Letters Patent. l

PatentedA sept. 14, 1909.

Application mea July 2o, 190s'. serial 110,444,523. y f

terior threads in which it is necessary to re-E verse the direction of rotation of the tool or tap so that it may be screwed out after the hole has been threaded. My invention has special reference or applicability to light,

and delicate work, and has for its objects; first. the provision of facilities for enabling comparatively inexperienced operators to se; eure the introduction and removal of the tap into and from the work squarely andl with precision; and, second, to secure the reversal of the direction of rotation of the tap easily and gently so as to prevent the breaking of the tap which is extremely liable to occur with taps of small diameter as such tools are hard and brittle.

I secure Athe abdve objects by means of the mechanism illustrated in the accompanying drawings, in which, A Figure 1 is a side elevation of amachine embmlyingl my invention; and, Fig. 2 .is a detail of the top of the machine, partially in section, showingthe lever mechanism for controlling the rotation of the tap.`

Similar reference numerals refer to similar parts throughout the several views.

The refeij'eiwc numeral 2 designates a base or foot, usual iirlike kinds of machinery, from which rises a column, 3. Slidably mounted upon the column, f3, lis the. plate" or table, 4, adapted to supportthe work dur-4 ing' the tapping operation. The top of the column, 3,' is provided with the branch, 5, curving' outwardly over the table, 4, and the branch, (i, extending' in an opposite direction to the branch, 5. Suitable bearings are provided inv the branches, 5 and (i, for mounting lthe. horizontally disposed shaft, 7, which is provided between its bearings with the drive pulley, The shaft, 7, extends beyond its bearinpgin the branch, 5, and upon the end thereof which is above. the table, 4, it is provided with the friction disk, 9. T he other end of the shaft, 7, extends only 'partially into the bearing', Ga, in the branch, 6. .The outer portion of the bearing, 6a, is threaded to aeconnnodate the knurled headed bolt, 6". The bolt,'6b, is provided with the lock nut, 6C. fIt is obvious that by .screwing the bolt,

GP, into the bearing, 6a, and locking it in po sition with thenut, 6C, the shaft-i' 7 and the ,-disk, 9, will be thrown forward for apurpose hereafter described.

*,The base or foot, 2, is provided with a mounting, 10, for the drive pulleys, 11 and y12, and an idler, 13. The idler, 13, and the vdrive pulley, 12, are adapted to'be connected byaa` belt not shown) inthe usual wa'y with a power shaft (also not shown). The drive pulley, 11, alines and is adapted to be connected'fby means of a belt with the drive pulley, 8, upon the shaft, 'L

The branch, 5, extends above-and over the friction disk, 9, and is provided upon its outer end with the vertically disposed bear'- ing, 14, and guide slot, 15. ,f

Revolubly and slidably mounted in the bearing, 14, is the spindle, 16, which is provide-d with the slot or spline, 1T, and upon its lower end with the chuck, 18, adapted to hold the tap. v

Upon the lower, portion of the spindle, 16,

,between the shoulders, 16a, and 16", is

mounted the collar, 16. One 'face of the collar, 16C, is provided with the rack, 19, which is engaged by the gear, Q0, carried by the rod,21, which revolves in the bearine, 09 in the branch, 5, and is operated by the handle, Q3, to advance the spindletoward and withdraw it from the table, 4.

To cause the spindle, 1G, to rotate, itis provided with the friction wheel, Q4, slid ably mounted thereon, and having a lug, if), extending therefrom into the slot or spline,. 17. The periphery of the friction wheel, 2li, contacts with and receives motion from the friction disk, 9. It is obvious that the point of contact between the disk, 9, and wheel, 24, v

"Q4, I have provided the rod, 25a, working in the guide slot, 15, the lower end of which is attached yto the ring, 26,Which projects into of the rod, 25a, is pivoted the` lever arm, 29,

'supported by the bracket, 30, carried by the branch, 5, and from the opposite end of the arm, 29, extends the rod, 3l, to the foot lever,

c 32. The foot lever, 32, is provided With the spring, 83, so that the operator can eoiitrol both the direction and speed of the tap by depressing or releasing the foot lever.

The threadedrod, 34, is provided for adjusting the elevation of the. table, 4, butV this is no portion of my present invention. The combination, however, of a proper positioning table with tap driving mechanism as above described is an extremely important and Valuable feature of the present invention, in that Without such a table the acenrac'y and precision of the Work is entirely dependent upon the experience of the mechanist. lith sncli a table and'such tap driving mechanism the relation of the work to the tool is determined, and liability of error, except through gross carelessness, is. excluded. J

By properly adjustingbr the bolt, (3, the, Jfriction between the disk, E), and Wheel, 24, can be so regulated that the spindle, 1.6, will cease to rotate at a point vvhere its further rotation would break the tap. This is an extremely useful possibility in tapping to the bottom of blind holes, as the operator has only to continue to run the machine until the tap ceases to rotate and then reverse the machine. All necessity for removing the tap for inspection during the progress of the ha ving' a splineivay therein. a friction ivheel I longitiidinallv ymovable thereon and having a lng` extendingr into said splineivay, a friction disk mounted at right angles with said .friction Wheel and in contact with the peripher)7 thereof. an annular collar extending' int-i, the hub of said friction wheel, a rod attached to said collar` a pivoted larm having one end connected \'\'ith said rod, a second rod passingl from the other end of said arni to a foot lever. and a spring for maintaining' :said rods and levers in one position.

ln tcstinion)Y hereof l have hereunto set in v hand in the presence of two witnesses.

' JOHN M. LRStHY. VtnQsSeS:

lV. lll. Alun'ris, ,Bi-:Nm T. lloomioi'sii. 

